The present invention relates generally to drainage pouches for use in collection of waste materials at the site of a colostomy or ileostomy and more specifically concerns a pouch susceptible to operation in either a vented or non-vented mode.
The natural accumulation of gases from the digestive system of an ostomy patient has provided a problem of long standing in the manufacture of waste collection pouches. This is so because an ostomy pouch is ideally tightly sealed at and around the stoma site and desirably the pouch and seal are imperivous to gases and liquids. Gases from the digestive system thus have a tendency to accumulate and "balloon" the gas-tight collection pouch and the ostomate frequently must initiate a small puncture in the pouch to release the gas. With a puncture of the pouch at almost any location, there exists a great likelihood of leakage of liquid wastes onto the outer garments of the ostomate.
Among the solutions proposed for venting of accumulating gases are providing pouches with a performed hole which is theoretically capable of being opened and re-sealed and providing a perforated tear-away corner on the pouch.
Providing re-closable holes and tear-away corners require costly manufacturing processes and have not adequately solved the problem. Leakage still occurs at re-closable holes due to their proximity to liquid wastes. Perforations necessary to develop tear-away corners will either be too shallow to make precise opening easy or will be too deep and destroy the vapor-tightness of the pouches, rendering them essentially permanently vented with no safeguards against liquid leakage.
Another prior art proposal relates to providing a permanent passage for gas escape which is an integral part of the pouch itself but which minimizes the likelihood that liquid waste material will also escape from the pouch. U.S. Pat. No. 3,055,368 discloses a permanently vented collection pouch of thermoplastic material provided with selectively placed heat seals which form a permanent, transversely-extending gas escape channel a the top of the pouch with laterally spaced-apart passages for open communication between the inside and outside of the pouch. While the leak-proof, continuously-venting pouches of the U.S. Pat. No. 3,055,368 involve no expensive extra manufacturing steps and are adequate for the needs of those patients for whom gas discharge is a chronic, recurrent problem, their use has not been widespread owing to the fact that continuous, unpredictable and involuntary venting through permanent gas escape passages and channels is frequently the cause of embarrassment for ostomates. It is generally the ostomate's desire that the pouch be initially of a non-vented variety which could be vented quickly and in private if and when excessive gas build-up occurs.
Because gas accumulation is not a problem for all ostomates and tends to vary in severity from day to day for any individual patient, providing permanently vented pouches for a segment of the ostomate population requires stocking of multiple types of pouches by the ostomate and by the pharmacist, hospital, or other supply source. The logistics of large scale stocking of vented and non-vented varieties of pouches by suppliers is compounded by the fact that pouches are already ordinarily stocked in multiple types according to stoma opening size.
Recent developments in ostomy pouch design of interest to the present invention include those of U.S. Pat. No. 3,931,819, whereby comfort to the skin of an ostomate is materially enhanced by providing a soft layer of thermoplastic material along the back of the pouch and heat-sealing the former about its entire periphery to the pouch itself. While the soft, insulating layer is ordinarily opaque, the heat seals or welds are not and they provide a transparent or at least translucent edge or rim about the entire perhiphery of the devices.